|
Dear
Xavier,
you
are right with the explanation of boundary identical.
However for boundary walls you can define a very small
convective heat transfer condition > 0.001 W/m²K. For alpha < 0.001 you
will receive direct contact (almost equivalent to > 999 W/m²K). We kept this
for backwards compatibility.
So if
you want to create a wall with mass towards the zone and the
adiabatic condition on the back (not in the middle of the wall as in
boundary identical mode), you might use following
approaches
1.
choose a low alpha e.g. 0.002 on the back of the boundary identical
wall
2. define the wall adjacent to a ficitve
zone with alpha_back = 999. In this fictive zone define a resistance only wall
with alpha_front = 999 and boundary identical to the back.
regards,
matthias
David,
With the 'identical' option, from what I
understood from the manual, what you do is to impose the condition that the
convective fluid in the back of the surface has the same temperature as the
'star temperature' from the front of the surface. In this way you create an
adiabatic plane INSIDE the wall, but not on the back surface (there are non
nule heat flows at both sides of the wall). What I was wondering is whether
you can impose an adiabatic condition straight on the BACK surface of the
wall.
Regards,
Xavier
----- Original Message -----
Sent: Thursday, December 02, 2004 5:26
PM
Subject: Re: [TRNSYS-users] Adiabatic
boundary wall in TYPE56
Dear Xavier,
With a BOUNDARY wall, you have the
option of defining the temperature on the other side of the wall as
"userdefined" (either an input, a constant value, or a schedule) or as
"identical." To define an adiabatic wall, simply set the boundary
temperature to "identical"
Kind regards,
David
At 10:14
AM 12/2/2004, Xavier García Casals wrote:
Hi,
Is there a direct way to specify an adiabatic boundary wall
in TYPE56?. From what I could find in the documentation, only boundary
walls with a boundary temperature may be deffined. In principle setting a
very small wall convection coefficient (HBACK) would fisically lead to an
adiabatic condition, but from the manual it seems it leads to the oposite
(wall temperature equal to boudary temperature). Two aproximations I can
think of are to specify the identical condition, in which case an
adiabatic plane would apear WITHIN the wall, or specifying a layer with a
very high resistence at the outer side of the wall. But is there not a way
to specify the boundary adiabatic condition
straight?
Regards,
Xavier
****************************************************************************************
Thermal
Energy System Specialists (TESS), LLC
David
BRADLEY
2916 Marketplace Drive - Suite 104
Partner
Madison, WI 53719
Phone: (608) 274-2577 USA
Fax: (608) 278-1475
E-mail: bradley@tess-inc.com
Web Pages: http://www.tess-inc.com
and http://www.trnsys.com
"Providing software
solutions for today's energy engineering projects"
****************************************************************************************
|